They were predicting Mad Max, and they still call the Brexiteers dumb.
That being said, the UK had an good deal in the EU, access to the markets without having to accept the dumb currency. which is why the EU played so rough with them, and is generally better off for them having left.
The problem is that the UK being between France and Germany, maybe because English is an unholy combination of French and German, was a stabilizing influence. When Europe finally faces the fact that they're no match for Russia and should just leave it alone, there will be nothing left but to turn on each other again. I suppose the winner can invade Russia again and lose, again.
But the fantasy that this stupid trade union meant that much was a collective elite hysteria. They couldn't just admit that they just liked to be able to travel and work in Europe like they were at home, because they knew most people couldn't actually afford to do that. Also, they loved the cheap labor, and that's another embarrassing thing to say out loud.